Question 6

(a) Discuss the meaning of an FRL of 120/90/60.

(b) You have been presented with the structural engineer’s plans for a proposed commercial building which detail its reinforced concrete elements.

The plans show a reinforced concrete framed building with 150mm thick suspended upper floor slabs that will be continuous over internal supporting columns and beams.

Assuming the slabs require an FRL of 180/180/180 specify the means recognised  by  the  NCC  as  acceptable  for  determining  whether  the construction illustrated and described will achieve this FRL.

(c) It is proposed to fire separate sole-occupancy units in a Class 2 building of Type A construction with solid gypsum block walls 110mm thick.  The FRL is to be determined in accordance with Specification A5.4.  Which of the following is a DTS Provision compliant solution?

(i)     A loadbearing wall 2.4m high?

(ii) A non-loadbearing wall 2.4m high?

(iii) A non-loadbearing wall 2.7m high?

(iv)  All of the above?

(d) Where an FRL is required for a wall (say an external wall) the expectation is

that the wall be able to achieve that FRL from all directions to which it may be exposed to fire (external and internal). However, the NCC does relax this expectation for certain circumstances and allows an external wall to be constructed to only have to resist an external fire (ie it permits brick veneer construction). Which DTS Provision permits this?